Most branching instructions (FI_CONDITION, FI_AND, FI_OR) linearize its
branches in a recursive way, while FI_SWITCH branches are linearized
from parser even before the switch instruction is allocated.
Change linearization of FI_SWITCH branches to make it similar to other
branching instructions. This also fixes an issue with constant
switch evaluation, where linearized branch is mistaken for
non-linearized during switch construction.
Thanks to Jiten Kumar Pathy for the bugreport.
Define scope for anonymous filters, and also explicitly distinguish block
scopes and function/filter scopes instead of using anonymous / named
distinction.
Anonymous filters forgot to push scope, so variables for them were in
fact defined in the top scope and therefore they shared a frame. This got
broken after rework of variables, which assumed that there is a named
scope for every function/filter.
For loops allow to iterate over elements in compound data like BGP paths
or community lists. The syntax is:
for [ <type> ] <variable> in <expr> do <command-body>
Allow variable declarations mixed with code, also in nested blocks with
proper scoping, and with variable initializers. E.g:
function fn(int a)
{
int b;
int c = 10;
if a > 20 then
{
b = 30;
int d = c * 2;
print a, b, c, d;
}
string s = "Hello";
}
When f_line is done, we have to pop the stack frame. The old code just
removed nominal number of args/vars. Change it to use stored ventry value
modified by number of returned values. This allows to allocate variables
on a stack frame during execution of f_lines instead of just at start.
But we need to know the number of returned values for a f_line. It is 1
for term, 0 for cmd. Store that to f_line during linearization.
When a new variable used the same name as an existing symbol in an outer
scope, then offset number was defined based on a scope of the existing
symbol ($3) instead of a scope of the new symbol (sym_). That can lead
to two variables sharing the same memory slot.
Direct recursion almost worked, just crashed on function signature check.
Split function parsing such that function signature is saved before
function body is processed. Recursive calls are marked so they can be
avoided during f_same() and similar code walking.
Also, include tower of hanoi solver as a test case.
Add literal for empty set [], which works both for tree-based sets
and prefix sets by using existing constant promotion mechanism.
Minor changes by committer.
All instructions with a return value (i.e. expressions, ones with
non-zero outval, third argument in INST()) should declare their return
type. Check that automatically by M4 macros.
Set outval of FI_RETURN to 0. The instruction adds one value to stack,
but syntactically it is a statement, not an expression.
Add fake return type declaration to FI_CALL, otherwise the automatic
check would fail builds.
Pass instructions of function call arguments as vararg arguments to
FI_CALL instruction constructor and move necessary magic from parser
code to interpreter / instruction code.
After switching to 16-way tries, trie format ignored unaligned / internal
prefixes and only reported the primary prefix of a trie node.
Fix trie format by showing internal prefixes based on the 'local' bitmask
of a node. Also do basic (intra-node) reconstruction of prefix patterns
by finding common subtrees in 'local' bitmask.
In future, we could improve that by doing inter-node reconstruction, so
prefixes entered as one pattern for a subtree (e.g. 192.168.0.0/18+)
would be reported as such, like with aligned prefixes.
Lexer expression for bytestring was too loose, accepting also
full-length IPv6 addresses. It should be restricted such that
colon is used between every byte or never.
Fix the regex and also add some test cases for it.
Thanks to Alexander Zubkov for the bugreport
Add operators .min and .max to find minumum or maximum element in sets
of types: clist, eclist, lclist. Example usage:
bgp_community.min
bgp_ext_community.max
filter(bgp_large_community, [(as1, as2, *)]).min
Signed-off-by: Alexander Zubkov <green@qrator.net>
For convenience, Trie functions generally accept as input values not only
NET_IPx types of nets, but also NET_VPNx and NET_ROAx types. But returned
values are always NET_IPx types.
The prefix trie now supports longest-prefix-match query by function
trie_match_longest_ipX() and it can be extended to iteration over all
covering prefixes for a given prefix (from longest to shortest) using
TRIE_WALK_TO_ROOT_IPx() macro.
Trie walking allows enumeration of prefixes in a trie in the usual
lexicographic order. Optionally, trie enumeration can be restricted
to a chosen subnet (and its descendants).
Add trie tests intended as benchmarks that use external datasets
instead of generated prefixes. As datasets are not included, they
are commented out by default.
Use 16-way (4bit) branching in prefix trie instead of basic binary
branching. The change makes IPv4 prefix sets almost 3x faster, but
with more memory consumption and much more complicated algorithm.
Together with a previous filter change, it makes IPv4 prefix sets
about ~4.3x faster and slightly smaller (on my test data).
For numeric operators, comma is used for disjunction in expressions like
"10, 20, 30..40". But for bitmask operators, comma is used for
conjunction in a way that does not really make much sense. Use always
explicit logical operators (&& and ||) to connect bitmask operators.
Thanks to Matt Corallo for the bugreport.
